1. Field
At least some exemplary embodiments described herein relate to semiconductor memories and, more particularly, relate to nonvolatile memory devices and methods of operating the same.
2. Description of the Related Art
Semiconductor memory device are memory devices implemented using semiconductors such as silicon (Si), germanium (Ge), gallium arsenide (GaAs), and indium phosphide (InP). In general, semiconductor memory devices are classified into volatile memory devices and nonvolatile memory devices.
The volatile memory devices may lose their stored data when their power supplies are interrupted. Volatile memory devices include a static RAM (SRAM), a dynamic RAM (DRAM), a synchronous DRAM (SDRAM), and the like. Nonvolatile memory devices retain their stored data even when their power supplies are interrupted. Nonvolatile memory devices include a read only memory (ROM), a programmable ROM (PROM), an electrically programmable ROM (EPROM), an electrically erasable and programmable ROM (EEPROM), a flash memory, a phase-change RAM (PRAM), a resistive RAM (RRAM), a ferroelectric RAM (FRAM), and the like.
With the recent advance in semiconductor technology, solid-state drives (SSDs) based on flash memory have been developed. Flash memory has the advantage of higher operating speed, lower power consumption, and lower noise than the conventional hard disk drive (HDD). However, the operating speed of flash memory is lower than the signal processing speed of a host or an application processor (AP) and signal transmission speed of an interface. Accordingly, various technologies have been developed to overcome the above disadvantage.